1. Field of the Invention
The present invention relates to a compact hoist that is configured for convenient assembly, disassembly and servicing and, more particularly, to a hoist having a sprocket, or other hoist wheel, that can be installed and removed without assembly and disassembly of the hoist transmission. Further, the present invention relates to a compact hoist that can employ a variety of differently configured sprockets or other hoist wheels.
2. Background of the Information
German Laid Open Patent No. 33 30 528 discloses an electrically operated compact chain hoist. The sprocket wheel of the hoist is located between the motor and the transmission of the hoist. With this design, the motor shaft and the drive shaft are coaxially positioned wherein the rapidly rotating outer drive shaft is powered by the slowly rotating inner output shaft. Although that design provides a good weight balance, there are, still, significant disadvantages. Some of the disadvantages include the lack of ease of assembly, lack of ease of maintenance, high replacement part costs for the parts subject to wear, and extremely low flexibility since the hoist cannot be equipped with winding devices other than a standard sprocket wheel or with larger sprocket wheel variants.
With that hoist, the sprocket wheel, which frequently becomes worn when subjected to intensive use, can only be replaced after dismantling the transmission and removing the motor. The transmission fluid must also be drained and then replaced.
When the sprocket wheel becomes worn, which occurs rapidly if the hoist is not lubricated regularly, the entire output shaft, which is designed as a single piece with the sprocket wheel, must be replaced. Since the housing acts as a chain guide and, therefore, narrowly encloses the sprocket wheel, varying designs of the sprocket wheel, e.g. sprocket wheels with a higher number of teeth or an increased diameter, or even the installation of cable drums which wind the cable in several layers, are not possible.